Regarding White Gaussian noise

Hey Ganesh,    Thanks for reaching out! So, I was trying to showcase what interval would include 3 standard deviations on each side. The 3 comes from the fact that for a Normal Distribution, 99.7% of all the data falls within this interval, so I wanted to showcase what the 3 deviations region would look like in this scenario.  Hope this helps!   Best,  365 Vik